Currently several more or less invasive devices and methods to perform a tracheostomy are available on the market and in literature.
The oldest and most used method is represented by the procedures of surgical trachestomy or cricothyroidotomy. The method consists in forming a surgical opening between the tracheal rings using surgical and traumatic tools like a scalpel and a dilator pincer. All this requires the activation of a surgical team, a sterilized environment and complex structures not always easy to find in emergency situations. The surgical opening of the trachea is complex, traumatic, requires the incision with a scalpel, opening an extended breach, tying the blood vessel, often a copious bleeding, a long anaesthesia, potential infective complications, and has a duration of about 30 minutes. This method can be preferred in some situations, for instance patients with a neck anatomy of difficult approach, but is not easy to be adopted in emergency situations, and moreover is very expensive for the tools and the personnel required.
In order to overcome these drawbacks, in the last years new tracheostomy techniques have been developed to place a tracheostomy tube with micro invasive techniques that allow not to use the classic surgical tracheostomy.
One of these techniques requires the use of dilator tools made of water-repellent plastic material. These dilators of increasing dimensions are introduced between the first tracheal rings through a small aperture obtained with a thick needle or with a scalpel. Then a wire guide is inserted to provide guidance for the insertion of the tubes or the dilator, to obtain a breach of size sufficient to allow placement of the tracheal tube. This technique requires a significant force on the longitudinal axis, and towards the posterior tracheal wall to be applied, in order to advance the dilators and to enlarge the breach to a size sufficient to allow placement of the tracheal tube.
The drawbacks of this technique are the long sequence of manipulations, a significant manual effort, the potential damages to the posterior tracheal wall produced by the rubbing of dilators during the advancing phase, the tissue separation in longitudinal direction, especially when using only one dilator.
One technique uses a curved cone shape dilator, similar to a rhinoceros horn, with increasing diameter from the distal to the proximal base; this requires a further step and an additional device to be placed inside the tube to help maintaining the tissues dilated and to allow overcoming obstacles.
Another method, similar to the previous one in the preparation and the use of a wire guide and as means for dilation a plastic tool provided on the distal portion of a screw thread that continues in the proximal direction with an increasing diameter up to a size sufficient for the tube to be inserted. The device inserted through a wire guide allows opening a breach between the tracheal rings with circular clockwise movements. This method carries on the limits of the previous one and can create an irregular breach with following protrusive scar on the tracheal lumen. Advantages of this technique are the possibility to keep the patient intubated and ventilated during the all the phases of dilation and placement of the tracheostomy tube.
Is also available a device that uses in alternative to the dilators an armed tracheal tube with a cuff at the distal end of a metallic sharp pointed groin. The metallic groin is tied to a metallic thread coming to the mouth from backwards, passed across the tracheal rings with a needle. Dragging the metallic wire with a significant force, the sharp pointed groin, trailing the tracheostomy tube will open a breach from inside the trachea outwards. This is a complex method with many difficulties, requiring a high manual skill and the need to perform some phases of the work very quickly as sometimes the patient cannot be intubated and ventilated.
In the recent years many devices have been designed for the percutaneus introduction of tracheal tubes using a dilator balloon in the dilation phase. However the insertion of the tracheal tube still represents a problem. Usually catheters with dilator balloon available in the market and used in angioplasty are used. The profile of these balloons doesn't allow friction to decrease when advancing in the trachea as the diameters remain fixed from the proximal to the distal end apart the tapering to tie to the wire guide (U.S. Pat. No. 7,036,510, US2005/094926, EP 784989). Moreover, no attention is given to the positioning of the inflation lumen in the dilator balloon, putting it also in proximal position. This generates the risk that during inflation the balloon is pushed backwards, when the inflated part is not inside the trachea yet.
Another device (EP 784989, U.S. Pat. No. 7,036,510) includes a balloon used only as a dilator, and not as introducer. The concept of handle is not developed to get the device easier to be manipulated and able to transmit precisely the thrust needed to introduce the tube, as well as the intermediate part of the device is not developed to grip tightly the tube during the dilation and advancing phases, to have a simple and rapid to be withdrawn once the tracheal tube is placed.
All these techniques require the patient to be intubated and ventilated, under endoscopic control. Then they are not suitable for emergency tracheostomy, namely when it is not possible to intubate the subject, and in cases of unstable cervical rachis fracture.